BMW DTC P1748 – Transmission Control Module Self-Test
DTC P1748 meaning on BMW
DTC P1748 on a BMW refers to a Transmission Control Module (TCM) Self-Test failure. This diagnostic trouble code indicates that the TCM has detected an issue during its self-diagnostic routine.
BMW DTC P1748 symptoms
Symptoms of DTC P1748 on a BMW may include erratic shifting behavior, transmission slipping, harsh shifting, or the transmission going into limp mode. The vehicle may also display a warning light on the dashboard indicating a transmission fault.
BMW DTC P1748 causes
The causes of DTC P1748 on a BMW can vary and may include faulty wiring connections, a malfunctioning TCM, low transmission fluid levels, or internal transmission issues. It is essential to perform a thorough diagnosis to pinpoint the exact cause.
BMW DTC P1748 seriousness
DTC P1748 should be taken seriously as it can lead to drivability issues and potential damage to the transmission if left unresolved. Ignoring this fault code may result in further transmission problems and could compromise the safety and performance of the vehicle.
How to diagnose DTC P1748 on BMW
To diagnose DTC P1748 on a BMW, a diagnostic scan tool capable of reading transmission fault codes is required. The technician will need to retrieve the specific fault code, check for any related codes, and perform a thorough inspection of the transmission system, including the TCM, wiring, and fluid levels.
How to fix DTC P1748 on BMW
Fixing DTC P1748 on a BMW involves addressing the root cause of the issue. This may include repairing any faulty wiring connections, replacing a malfunctioning TCM, ensuring proper transmission fluid levels, or conducting necessary transmission repairs. It is recommended to follow the manufacturer’s diagnostic and repair procedures.
How to erase DTC P1748 on BMW
Once the underlying issue causing DTC P1748 on a BMW has been resolved, the fault code can be cleared using a diagnostic scan tool. By erasing the fault code, the TCM will re-run its self-test to ensure the problem has been rectified. It is important to verify that the fault code does not return after clearing it.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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